Philip Keyes Yonge was born in Marianna, Florida, on May 27, 1850. He was educated in private schools and finished his education at the University of Georgia in 1872 with the degree of LL.B. He served briefly in the British consulate in Pensacola before joining the Muscogee Lumber Company in 1876. He remained in the lumber industry for the rest of this life. In 1889, Muscogee was acquired by the Southern States and Timber Company which became Southern State Lumber Company in 1898. Yonge became president and manager of the company in 1903. Yonge was active in Pensacola's civic and political affairs throughout his life. He served terms as alderman, on the Board of Public Instruction, and as president of the Chamber of Commerce.

In 1905, Yonge was appointed to the newly created Florida Board of Control, Florida's governing board for public higher education, by Governor Napoleon Bonaparte Broward. Members served concurrently on the State Plant Board. In 1909, Yonge became chair of both boards. He was not reappointed by Governor Sidney Catts in 1917, but returned as chair in 1921. He retained that position until he retired in 1933.

Yonge was an avid collector of Floridiana and helped revive the Florida Historical Society in 1902. He served as president of the society from 1932 until his death in 1934. His extensive collection of books and documents passed to this son, Julien C. Yonge, who further expanded the collection. Julien Yonge donated the collection to the University of Florida as the nucleus of today's P.K. Yonge Library of Florida History.

The Yonge Papers are limited to correspondence, reports, minutes and other documents related to Yonge's service on the Florida Board of Control and Florida State Plant Board. As such, it is one of the richest sources of information on public higher education in Florida in the years following the passage of the Buckman Act of 1905 which consolidated the public colleges under one governing board. It is also a valuable source on major issues related to Florida agriculture, particularly disease eradication and applied research.

There is considerable material on building programs at the college campuses, on the Farmers Institutes and the Agricultural Experiment Station, and on the creation of the first agricultural substations in Lake Alfred, Belle Glade, and Quincy. The collection contains detailed financial reports from each state college. The latter includes reports on Florida State's Westcott Estate. Of particular interest are the extensive records related to plant diseases and infestations beginning with the citrus canker eradication program of 1915, the later Mediterranean Fruit Fly campaign, and the appearance of mosaic disease in the sugar industry in the 1920s. Also of note are the records related to the disturbances at Florida A and M College following the dismissal of President Nathan B. Young in 1923. Also chronicled in the collection is the continuous conflict between the Florida Board of Education and the Board of Control over who ultimately controlled public higher education.

Arranged chronologically by month. There are major gaps in the collection. Papers are missing for January 1911 through March 1915. Other gaps appear between November 1922 and May 1923, November 1924 and May 1925, March and July 1928, and May and December 1931. There is very little for September and October 1924.